Badejo M Adetola, Espindola Jose Antonio Azevedo, Guerra Jose Guilherme Marinho, De Aquino Adriana Maria, Correa Maria Elizabeth Fernandes
Department of Zoology, Obafemi Awolowo University, Ile-lfe, Nigeria.
Exp Appl Acarol. 2002;27(4):283-96. doi: 10.1023/a:1023399607317.
Oribatid mite densities in the topsoil and their activity at the soil surface were monitored under three species of perennial legume cover crops namely, Arachis pintoi, Macroptilium atropupureum and Pueraria phaseoloides, grass (Panicum maximum) and bare plots on three occasions in 1998 and 1999 in a derived savanna zone in Brazil. Both densities and activity at the soil surface were higher in the early but cool dry season in April 1998 than in the early wet but warm season in November 1998 and 1999. Three taxonomic groups of macropyline oribatid mites, namely Nothrus, Archegozetes and Masthermannia as well as a brachypyline taxon, Scheloribates were suggested as possible indicators of effect of legumes on soil biota because their populations increased under the legumes and/or the irresidues. Nothrus in particular increased in abundance more than any other taxon in the presence of residues of A. pintoi. Each legume supported a unique oribatid mite community in terms of species composition and relative abundance. The large numbers of Archegozeres trapped from all the legume and grass plots in April and November 1998 were also attributed to highly conducive conditions provided by the vegetation cover and their residues. The results suggest that the oribatid mite community of the study area was numerically stable as the peak populations of different species were not synchronized. Many taxonomic groups of pycnonotic brachypyline mites were absent. Legume cover crops, especially A. pintoi, and their residues have potential in restoring oribatid mite populations to precultivation levels.
1998年和1999年，在巴西一个次生稀树草原区，对三种多年生豆科覆盖作物（即平托落花生、大翼豆和葛藤）、禾本科植物（大黍）以及裸地的表土中甲螨密度及其在土壤表面的活动进行了三次监测。1998年4月初凉爽干燥季节的土壤表面密度和活动均高于1998年11月以及1999年11月初湿润温暖季节。三种大翼甲螨分类群，即诺氏甲螨属、原革甲螨属和马斯甲螨属以及一个短翼甲螨分类群，革甲螨属，被认为可能是豆科植物对土壤生物群影响的指标，因为它们的种群数量在豆科植物和/或其残体下有所增加。特别是在有平托落花生残体存在时，诺氏甲螨属的数量增加幅度超过其他任何分类群。就物种组成和相对丰度而言，每种豆科植物都支持一个独特的甲螨群落。1998年4月和11月从所有豆科植物和禾本科植物地块诱捕到的大量原革甲螨也归因于植被覆盖及其残体提供的高度有利条件。结果表明，研究区域的甲螨群落数量稳定，因为不同物种的种群峰值并不同步。许多紧实短翼甲螨分类群不存在。豆科覆盖作物，特别是平托落花生及其残体，有潜力将甲螨种群数量恢复到耕种前的水平。
